Mapping disease spread

ABSTRACT

Disclosed are systems and methods for mapping a patient&#39;s lymphatic system. An exemplary method includes generating a three-dimensional (3D) model of a bronchial network in the patient&#39;s chest, generating a lymphatic tree map by fitting a model lymph node map to the 3D model, receiving locations of a plurality of identified lymph nodes, updating the positions of lymph nodes on the lymphatic tree map, and displaying the updated lymphatic tree map.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of provisionalU.S. Patent Application No. 62/624,905, filed Feb. 1, 2018, the entirecontents of which are incorporated herein by reference.

BACKGROUND

Diagnosis and treatment of disease, such as cancer, in a patient's lungsrequire knowledge of the internal anatomy of the patient's chest. Thepatient's chest includes various structures and distributed networks,such as the bronchial, vascular, and lymphatic systems, and thelocations of such structures as well as the patterns of flow in everypatient are unique. Larger structures and lumens may be identified viaanalysis of radiographic images of the patient's chest. However, smallerstructures may not be identifiable based on image analysis. Thus, it ishard to visualize smaller structures in a patient's chest withoutexploratory or interventional procedures. It is preferable to be able todiagnose the degree to which cancer has developed and spread though thepatient's body without resorting to extensive interventional procedures.This process is also known as cancer staging.

For example, to determine the extent to which cancer has developed andspread through a patient's body, in the case of solid tumors, aclinician may follow the Union for International Cancer Control's (UICC)TNM staging system to determine the size and/or extent of the primarytumor, a degree of spread to the lymphatic system, and the presence ofdistant metastasis. The UICC's TNM staging system considers the primarytumor (T), regional lymph nodes (N), and distant metastasis (M) todescribe the size and spread of cancer through the patient's body.Cancer may spread via the lymphatic or vascular systems as cancer cellsbreak off from tumors and find their way into lymph nodes and vessels.The cancer cells may then be distributed via the lymphatic and/orvascular systems and thereby spread to other parts of the patient'sbody.

SUMMARY

Provided in accordance with an embodiment of this disclosure is a methodfor mapping a patient's lymphatic system. In an aspect of thisdisclosure, the method includes generating a three-dimensional (3D)model of a bronchial network and vascular network in the patient's chestbased on first image data of the patient's chest, generating a lymphatictree map by fitting a model lymph node map to the 3D model, receivinglocations of a plurality of identified lymph nodes, updating thepositions of lymph nodes on the lymphatic tree map by correlating thelocations of the plurality of identified lymph nodes with the lymphatictree map, and displaying the updated lymphatic tree map.

In a further aspect of the disclosure, the lymph nodes are identifiedbased on image processing of the first image data.

In yet a further aspect of the disclosure, the plurality of lymph nodesare identified based on electromagnetic sensor (EM) data received froman EM sensor coupled to a tool being navigated about the patient'schest.

In still a further aspect of the disclosure, the lymph nodes areidentified based on return signals received from a linear ultrasoundscope.

In yet a further aspect of the disclosure, the lymph nodes areidentified using spectroscopy.

In another aspect of the disclosure, the method further includesidentifying a lesion in the 3D model.

In yet another aspect of the disclosure, the method further includesreceiving second image data of the patient's chest, identifying aradiopaque element injected into a target in the second image data, anddetermining a distribution path from the target based on the identifiedradiopaque element and the updated lymphatic tree map.

In a further aspect of the disclosure, the target is a lymph nodeproximate the identified lesion.

In still a further aspect of the disclosure, the radiopaque element isone of radio-tagged whole blood from the patient, a collagen tracer, ora radiation tracer.

In another aspect of the disclosure, the method further includesidentifying a sentinel lymph node based on the distribution path, anddisplaying the identified sentinel lymph node on the updated lymphatictree map.

In yet another aspect of the disclosure, the method further includesidentifying a lymph node in the distribution path a predetermineddistance from the sentinel lymph node, and displaying the identifiedlymph node on the updated lymphatic tree map.

In a further aspect of the disclosure, the predetermined distance is atleast about 5 cm.

In yet a further aspect of the disclosure, the predetermined distance isbetween about 7 cm and about 10 cm.

In still a further aspect of the disclosure, the identified lymph nodeis a lymph node with at least three other lymph nodes between theidentified lymph node and the sentinel lymph node.

In another aspect of the disclosure, the method further includesdetermining areas to which spread may occur based on the identifiedsentinel lymph node and the distribution path, and displaying the areasto which spread may occur on the updated lymphatic tree map.

In a further aspect of the disclosure, the model lymph node map is theInternational Association for the Study of Lung Cancer (IASLC) lymphnode map.

Provided in accordance with an embodiment of the disclosure is a methodfor mapping a patient's vascular system. In an aspect of the disclosure,the method includes generating a three-dimensional (3D) model of abronchial network in the patient's chest based on image data of thepatient's chest, generating a vascular tree map by fitting a modelvascular map to the 3D model, receiving locations of a plurality ofidentified vascular structures, updating the positions of vascularstructures on the vascular tree map by correlating the locations of theplurality of identified vascular structures with the vascular tree map,and displaying the updated vascular tree map.

In a further aspect of the disclosure, the plurality of vascularstructures are identified based on electromagnetic sensor (EM) datareceived from an EM sensor coupled to a tool being navigated about thepatient's chest.

Provided in accordance with an embodiment of the disclosure is a methodfor mapping a patient's lymphatic system. In an aspect of thedisclosure, the method includes receiving image data of a patient'schest, generating a three-dimensional (3D) model of a bronchial networkbased on the received image data, generating a lymphatic tree map byfitting a model lymph node map to the generated 3D model, receivinglocations of a plurality of identified lymph nodes based onelectromagnetic sensor (EM) data received from an EM sensor coupled to atool being navigated about the patient's chest, and updating thepositions of lymph nodes on the lymphatic tree map based on thelocations of the plurality of identified lymph nodes.

In a further aspect of the disclosure, the method further includesdisplaying the updated lymphatic tree map.

Any of the above aspects and embodiments of the disclosure may becombined without departing from the scope of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects and features of this disclosure are describedhereinbelow with references to the drawings, wherein:

FIG. 1 is a schematic diagram of a system for planning and performingtreatment of an area of a patient's chest endobronchially, according toan embodiment of the disclosure;

FIG. 2 is a schematic diagram of a system for planning and performingtreatment of an area of a patient's chest percutaneously and/orlaparoscopically, according to an embodiment of the disclosure;

FIGS. 3A and 3B show a flowchart of an example method for predictingspread of disease based on a lymphatic tree map, according to anembodiment of the disclosure;

FIG. 4 is an exemplary graphical user interface showing an airway treeand lymphatic tree map, according to an embodiment of the disclosure;and

FIG. 5 is a block diagram of an example computing device forming part ofthe systems of FIG. 1 and/or FIG. 2.

DETAILED DESCRIPTION

Current methodologies for locating and identifying lymph nodes,lymphatic networks, and vascular networks, as well as theirrelationships to one another, often rely primarily on the abilities ofthe clinician. Improvements in systems and methods to aid the clinicianin identifying and mapping locations of lymph nodes, lymphatic networks,and vascular networks, as well as their relationships to one another,are desired.

This disclosure relates to systems and methods for mapping a patient'slymphatic and vascular systems, and predicting spread of disease basedon distribution patterns of, and interrelation between, the patient'slymphatic and vascular systems and the target area itself. Moreparticularly, the disclosure relates to fitting a model lymphatic treemap and/or model vascular tree map to a model of the patient's bronchialnetwork, updating the map with the actual locations of the patient'slymph nodes and/or vascular structures, identifying one or more sentinellymph nodes and/or vascular structures which may form distribution pathsby which disease may spread from a lesion, and predicting where diseaseis most likely to spread based on the identified sentinel lymph nodesand/or vascular structures. Pre-procedural imaging of the patient'schest may be performed to create a visual representation, such as athree-dimensional (3D) model of a patient's chest, including lumens suchas the bronchial, vascular, and lymphatic trees, pleural surfaces andfissures of the patient's lungs, and/or tumors or other aberrantstructures that may be present in the patient's lungs. The 3D model maybe generated using one or more software applications executing on acomputer. The application may, for example, generate the 3D model or mapof the patient's chest based on radiographically obtained images, suchas computed tomography (CT) images, magnetic resonance imaging (MRI)images, positron emission tomography (PET) images, X-ray images,cone-beam computed tomography (CBCT) images, and/or fluoroscopic images,as well as ultrasound images, and/or any other applicable imagingmodality. The images may be processed to create a volume of image dataof the patient's chest based upon which the 3D model is generated. Theimage data and/or 3D model may further be processed to identify one ormore targets, such as tumors, lesions, or other aberrant structures, inthe patient's chest. For example, the application may identify thelocations of lumens, such as airways, blood vessels, and/or lymphaticstructures from the CT image data, and further determine the locationsof one or more diagnostic or treatment targets (referred to hereinafteras “targets”).

The application may then receive or load a model lymph node map, such asthe International Association for the Study of Lung Cancer (IASLC) map,which includes the locations of lymph nodes in a model patient's body.Thereafter, the application may fit the model lymph node map to the 3Dmodel to align the model map with the real patient's body and theidentified structures in the patient's chest. A lymphatic tree map ofthe patient's lymphatic system may then be generated based on the modellymph node map fitted to the 3D model. The generated lymphatic tree mapmay further be fitted and/or updated based on known locations of lymphnodes in the patient's chest. For example, the lymphatic tree map may beupdated based on locations of lymph nodes identified based on the imagedata and/or based on location data of tools used to sample, such as viabiopsy, lymph nodes in the patient's body.

The 3D model, radiographic image data, and lymphatic tree map may thenbe displayed to and viewed by a clinician and/or surgeon to plan amedical procedure, such as a diagnostic or treatment procedure,including biopsy, ablation, radiation, and/or surgical or interventionalprocedure. For example, the clinician may review the 3D model,radiographic image data, and/or lymphatic tree map to identify a lesionor other target for diagnosis and/or treatment. The application may thendetermine a path to the lesion or target, as further described below.The 3D model, lymphatic tree map, and/or procedure plan may further bestored for later viewing during the medical procedure in an operatingroom or the like.

Additionally, the application may receive, load, or generate a vasculartree map of the patient's vascular system. In some embodiments, a modelvascular tree map of vascular structures in a model patient's body maybe fitted to the 3D model to align the model vascular tree map with thereal patient's body. A vascular tree map of the patient's vascularsystem may then be generated based on the model vascular tree map fittedto the 3D model. Additionally or alternatively, the application mayprocess the radiographic image data and/or 3D model to identify vascularstructures in the patient's body and generate the vascular tree mapbased on such identified vascular structures.

During the medical procedure, the 3D model, vascular tree map, and/orlymphatic tree map may be displayed, as further described below, toassist the clinician in navigating one or more tools to one or moretargets. For example, the clinician may biopsy a lesion and/or lymphnode to obtain a tissue sample which may be analyzed to determine ifcancer cells are present. A radiopaque element, such as a dye, tracer,or radio-tagged fluid, or other elements such as radioisotopes, etc.,may be injected into a lesion or target to identify distribution and/ordrainage paths from the lesion or target.

After the radiopaque element has been injected into one or more lesionsor targets, additional image data may be acquired to identify thedistribution and/or drainage paths from the lesions or targets. Forexample, the application may process the additional image data toidentify lymphatic lumens and nodes as well as blood vessels via whichthe radiopaque element has drained after injection. The application maythen identify, based on the distribution and/or drainage paths, one ormore sentinel lymph nodes, and predicted disease spread from the lesionor target, as well as vascular ingress and egress from the target and/orarea surrounding the target.

The methods, systems, apparatus, and computer-readable media describedherein are useful in various planning and/or navigation contexts fordiagnostic and/or treatment procedures performed in the patient's chest.For example, in an embodiment in which a clinician is performingdiagnosis of lesions in an area of the patient's lungs, the methods andsystems may provide the clinician with various views of the patient'slungs and the bronchial, vascular, and lymphatic trees therein.Additionally, as will be described in further detail below, the methodsand systems may provide the clinician with the ability viewdistribution/drainage paths from the lesions via the lymphatic andvascular systems to predict spread of disease. These and other aspectsof this disclosure are detailed hereinbelow.

Methods for planning and performing diagnosis and/or treatment in apatient's chest may be implemented via an electromagnetic navigation(EMN) system. Generally, in an embodiment, the EMN system may be used inplanning diagnosis and/or treatment of an area of the patient's chest byidentifying the locations of one or more targets in the patient's chest,selecting one or more of the targets as a target location, determining apathway to the target location, navigating a positioning assembly to thetarget location, and navigating a variety of tools to the targetlocation. Once at the target location, the EMN system may be used to aidthe clinician in placing one or more tools at the target location andperforming one or more diagnostic and/or treatment functions at thetarget location. The EMN system may be configured to display variousviews of the patient's body, and of the aforementioned 3D model,lymphatic tree map, and/or vascular tree map.

FIG. 1 illustrates an EMN system 100 suitable for implementing methodsfor performing endobronchial diagnostic and/or treatment procedures inan area of a patient's chest is provided in accordance with thisdisclosure. One such EMN system 100 is the ELECTROMAGNETIC NAVIGATIONBRONCHOSCOPY® system currently sold by Covidien LP, a division ofMedtronic PLC. As shown in FIG. 1, EMN system 100 is used to perform oneor more treatment procedures on a patient supported on an operatingtable 40. In this regard, EMN system 100 generally includes abronchoscope 50, monitoring equipment 30, an electromagnetic (EM)tracking system 70, and a computing device 80.

Bronchoscope 50 is configured for insertion through the patient's mouthand/or nose into the patient's airways. Bronchoscope 50 includes asource of illumination and a video imaging system (not explicitly shown)and is coupled to monitoring equipment 30, for example, a video display,for displaying the video images received from the video imaging systemof bronchoscope 50. In an embodiment, bronchoscope 50 may operate inconjunction with a catheter guide assembly 90. Catheter guide assembly90 includes a locatable guide (LG) 92 and an extended working channel(EWC) 96 configured for insertion through a working channel ofbronchoscope 50 into the patient's airways (although the catheter guideassembly 90 may alternatively be used without bronchoscope 50). Catheterguide assembly 90 includes a handle 91 connected to EWC 96, and whichcan be manipulated by rotation and compression to steer LG 92 and EWC96. EWC 96 is sized for placement into the working channel ofbronchoscope 50. In the operation of catheter guide assembly 90, LG 92,including an EM sensor 94, is inserted into EWC 96 and locked intoposition such that EM sensor 94 extends a desired distance beyond adistal tip 93 of EWC 96. The location of EM sensor 94, and thus distaltip 93 of EWC 96, within an EM field generated by EM field generator 76,can be derived by tracking module 72 and computing device 80. For a moredetailed description of catheter guide assembly 90, reference is made tocommonly-owned U.S. Pat. No. 9,247,992, entitled “MICROWAVE ABLATIONCATHETER AND METHOD OF UTILIZING THE SAME”, filed on Mar. 15, 2013, byLadtkow et al., the entire contents of which are hereby incorporated byreference.

LG 92 and EWC 96 are selectively lockable relative to one another via alocking mechanism 99. A six degrees-of-freedom EM tracking system 70,e.g., similar to those disclosed in U.S. Pat. No. 6,188,355 andpublished PCT Application Nos. WO 00/10456 and WO 01/67035, entitled“WIRELESS SIX-DEGREE-OF-FREEDOM LOCATOR”, filed on Dec. 14, 1998 byGilboa, the entire contents of each of which is incorporated herein byreference, or any other suitable positioning measuring system, isutilized for performing navigation, although other configurations arealso contemplated.

EM tracking system 70 may be configured for use with catheter guideassembly 90 to track a position of EM sensor 94 as it moves inconjunction with EWC 96 through the airways of the patient, as detailedbelow. In an embodiment, EM tracking system 70 includes a trackingmodule 72, a plurality of reference sensors 74, and an EM fieldgenerator 76. As shown in FIG. 1, EM field generator 76 is positionedbeneath the patient. EM field generator 76 and the plurality ofreference sensors 74 are interconnected with tracking module 72, whichderives the location of each reference sensor 74 in the six degrees offreedom. One or more of reference sensors 74 are attached to the chestof the patient. The six degrees of freedom coordinates of referencesensors 74 are sent as data to computing device 80, which includesapplication 81, where the data from sensors 74 are used to calculate apatient coordinate frame of reference.

Although EM sensor 94 is described above as being included in LG 92 itis also envisioned that EM sensor 94 may be embedded or incorporatedwithin a treatment tool, such as a biopsy tool 62 and/or an ablationtool 64, or a diagnostic tool, such as camera tool, light sensor, linearultrasound tool, etc., where the treatment tool may alternatively beutilized for navigation without need of LG 92 or the necessary toolexchanges that use of LG 92 requires. EM sensor 94 may also be embeddedor incorporated within EWC 96, such as at a distal portion of EWC 96,thereby enabling tracking of the distal portion of EWC 96 without theneed for a separate LG 92. According to an embodiment, treatment tools62, 64 are configured to be insertable into catheter guide assembly 90following navigation to a target location and removal of LG 92. Biopsytool 62 may be used to collect one or more tissue sample from the targetlocation, and in an embodiment, is further configured for use inconjunction with tracking system 70 to facilitate navigation of biopsytool 62 to the target location, and tracking of a location of biopsytool 62 as it is manipulated relative to the target location to obtainthe tissue sample. Ablation tool 64 is configured to be operated with agenerator 66, such as a radio frequency generator or a microwavegenerator, and may include any of a variety of ablation tools and/orcatheters, examples of which are more fully described in U.S. Pat. Nos.9,259,269; 9,247,993; 9,044,254; and 9,370,398, and U.S. PatentApplication Publication No. 2014/0046211, all entitled “MICROWAVEABLATION CATHETER AND METHOD OF USING THE SAME”, filed on Mar. 15, 2013,by Ladtkow et al., the entire contents of each of which is incorporatedherein by reference. Though shown as a biopsy tool and microwaveablation tool in FIG. 1, those of skill in the art will recognize thatother tools including for example RF ablation tools, brachytherapytools, endobronchial ultrasound devices, and others may be similarlydeployed and tracked without departing from the scope of thisdisclosure.

Computing device 80 includes hardware and/or software, such as anapplication 81, used to facilitate the various phases of an EMNprocedure, including generating the 3D model, generating the lymphatictree map, identifying a target location, planning a pathway to thetarget location, registering the 3D model with the patient's actualairways, and navigating to the target location. Application 81 mayfurther be used to process image data to determine distribution/drainagepaths from a lesion and predict spread of disease, as further describedbelow. For example, computing device 80 utilizes data acquired from a CTscan, cone beam computed tomography (CBCT) scan, magnetic resonanceimaging (MRI) scan, positron emission tomography (PET) scan, ultrasoundscan, X-ray scan, and/or any other suitable imaging modality to generateand display the 3D model of the patient's airways, to enableidentification of a target location on the 3D model (automatically,semi-automatically or manually), and allow for the determination andselection of a pathway through the patient's airways to the targetlocation. While the CT scan image data may have gaps, omissions, and/orother imperfections included in the image data, the 3D model is a smoothrepresentation of the patient's airways, with any such gaps, omissions,and/or imperfections in the CT scan image data filled in or corrected.The 3D model may be presented on a display monitor associated withcomputing device 80, or in any other suitable fashion. An example of theplanning software described herein can be found in U.S. PatentApplication Publication Nos. 2014/0281961, 2014/0270441, and2014/0282216, filed by Baker et al. on Mar. 15, 2013, and entitled“PATHWAY PLANNING SYSTEM AND METHOD”, the contents of all of which areincorporated herein by reference. Further examples of the planningsoftware can be found in commonly assigned U.S. Patent ApplicationPublication No. 2016/0000302, entitled “SYSTEM AND METHOD FOR NAVIGATINGWITHIN THE LUNG”, filed on Jun. 29, 2015, by Brown et al., the contentsof which are incorporated herein by reference.

Using computing device 80, various views of the 3D model and/orlymphatic tree map may be displayed to and manipulated by a clinician tofacilitate identification of a target location. As noted above, thetarget location may be a surgical site where treatment is to beperformed, and/or a portion of, entire lobe, or multiple lobes of thepatient's lungs requiring treatment. The 3D model may include, amongother things, a model airway tree corresponding to the actual airways ofthe patient's lungs, and show the various passages, branches, andbifurcations of the patient's actual airway tree. Additionally, the 3Dmodel may include lesions, markers, blood vessels and vascularstructures, organs, other physiological structures, and/or a 3Drendering of the pleural surfaces and fissures of the patient's lungs.Some or all of the aforementioned elements may be selectively displayed,such that the clinician may choose which elements should be displayedwhen viewing the 3D model. Additionally, the lymphatic tree map may bedisplayed as part of the 3D model or as a separate map which may beoverlaid onto the 3D model.

During a procedure, EM sensor 94, in conjunction with tracking system70, enables tracking of EM sensor 94 (and thus distal tip 93 of EWC 96or tools 62, 64) as EM sensor 94 is advanced through the patient'sairways following the pathway planned during the planning phase. As aninitial step of the procedure, the 3D model is registered with thepatient's actual airways. One potential method of registration involvesnavigating LG 92 into each lobe of the patient's lungs to at least thesecond bifurcation of the airways of that lobe. The position of LG 92 istracked during this registration phase, and the 3D model is iterativelyupdated based on the tracked position of the locatable guide within theactual airways of the patient's lungs. This registration process isdescribed in commonly-owned U.S. Patent Application Publication No.2011/0085720, entitled “AUTOMATIC REGISTRATION TECHNIQUE,” filed on May14, 2010, by Barak et al., and U.S. Patent Publication No. 2016/0000356,entitled “REAL-TIME AUTOMATIC REGISTRATION FEEDBACK”, filed on Jul. 2,2015, by Brown et al., the contents of each of which are incorporatedherein by reference. While the registration process focuses on aligningthe patient's actual airways with the airways of the 3D model,registration also ensures that the position of vascular structures,pleural surfaces, and fissures of the lungs are accurately determined.

At various times during the procedure, the clinician may causeadditional scans to be performed on the patient. These additional scansmay be used to determine distribution/drainage paths from a lesionand/or lymph node by identifying drainage, via the lymphatic and/orvascular systems, of a radiopaque element that has been injected intothe lesion and/or lymph node. As such, the additional scans may befluoroscopic scans, but those skilled in the art will recognize thatother imaging modalities may also be used. For example, CBCT imaging,C-arm x-ray imaging, and/or any other applicable imaging modality mayalso be used without departing from the scope of this disclosure. Theadditional scans may be directed at a particular location in thepatient's chest where the lesion and/or lymph node that has beeninjected with the radiopaque element is located. Application 81 mayreceive the image data acquired by the additional scans and process theimage data to identify the radiopaque element and determine distributionpaths from the lesion and/or lymph node based on the drainage of theradiopaque element.

Application 81 may then update and/or enhance the lymphatic tree mapand/or vascular tree map based on the additional image data, andparticularly, the determined distribution paths. Application 81 mayfurther identify lymphatic and/or vascular structures in the additionalimage data and update and/or enhance the lymphatic tree map and/orvascular tree map based on the identified lymphatic and/or vascularstructures that are in different locations and/or not previouslyincluded in the lymphatic tree map and/or vascular tree map. Forexample, the additional image data may provide a clearer image of theparticular part of the patient's body that was imaged by the additionalscan than by the original scan, and application 81 may update and/orenhance a portion of the lymphatic tree map and/or vascular tree mapbased on the additional image data. Application 81 may then display theupdated lymphatic tree map and/or vascular tree map showing thedetermined distribution paths.

After determining the distribution paths, application 81 may determine,based on the distribution paths, a type of disease being diagnosedand/or treated, and/or input from the clinician, one or more lymph nodesfrom which to obtain a biopsy sample to determine if the disease hasspread to such lymph nodes. Additionally or alternatively, in the caseof surgery, application 81 may determine whether it is necessary toremove a portion of tissue from the patient's body. Application 81 maythen generate a plan for obtaining the biopsy samples, similar to thenavigation plan described above.

Turning now to FIG. 2, there is shown a system 200 suitable forimplementing methods for performing percutaneous and/or laparoscopicdiagnostic and/or treatment procedures in an area of a patient's chest,in accordance with embodiments of this disclosure. System 200 includes adisplay 210, a table 220 including an electromagnetic (EM) fieldgenerator 221, a tool 230, an ultrasound sensor 240 connected to anultrasound workstation 250, a peristaltic pump 260, and a computingdevice 80 attached to or in operable communication with a microwavegenerator 270. Computing device 80 may be similar to the computingdevice 80 described above with reference to FIG. 1. In addition,computing device 80 may be configured to control microwave generator270, peristaltic pump 260, a power supply (not shown), and/or any otheraccessories and peripheral devices relating to, or forming part of,system 200. Display 210 is configured to output instructions, images,and messages relating to the performance of the medical procedure.

Table 220 may be, for example, an operating table or other tablesuitable for use during a medical procedure, which includes EM fieldgenerator 221. EM field generator 221 is used to generate an EM fieldduring the medical procedure and forms part of an EM tracking systemthat is used to track the positions of tools within the patient's chest.EM field generator 221 may include various components, such as aspecially designed pad to be placed under, or integrated into, anoperating table or patient bed. An example of such an EM tracking systemis the AURORA™ system sold by Northern Digital Inc.

Tool 230 is a medical instrument for accessing and performing diagnosticand/or treatment procedures at a target location. For example, tool 230may be biopsy needle used to obtain a tissue sample from a targetlocation in the patient's chest. In another example, tool 230 may be anablation antenna, such as an RF or microwave ablation antenna, used toablate the target location in the patient's chest. In yet anotherembodiment, tool 230 may include a camera, such as a laparoscope,ultrasound probe, or other device for capturing images (whether opticalor radiographic) inside the patient's body. In some embodiments, tool230 is a percutaneous tool insertable through the patient's skin toaccess one or more target locations. In other embodiments, tool 230 is alaparoscopic tool insertable into the patient's body via a laparoscopicport or trocar. Multiple tools may be used simultaneously, and in thecase of laparoscopic tools, multiple laparoscopic ports or trocars maybe used simultaneously. In various embodiments, tool 230 may be arobotic tool associated with a robotic surgical system, or a manual tooloperated by the clinician. Tool 230 may include, or have attached to it,and EM sensor enabling the EM tracking system to track the location,position, and orientation (also known as the “pose”) of tool 230 insidethe patient's chest. If tool 230 is a microwave ablation antenna,microwave generator 270 may be configured to output microwave energy totool 230. Peristaltic pump 260 may be configured to pump fluid throughtool 230 to cool tool 230. While this disclosure describes the use ofsystem 200 in a surgical environment, it is also envisioned that some orall of the components of system 200 may be used in alternative settings,for example, an imaging laboratory and/or an office setting.

In addition to the EM tracking system, the above-described instruments,including tool 230, may also be visualized by using ultrasound imaging.Ultrasound sensor 240, such as an ultrasound wand, may be used to imageone or more portions of the patient's chest during the medical procedureto visualize the location of the instruments, such as tool 230, insidethe patient's chest, for example, to confirm the position and/orplacement of tool 230. Ultrasound sensor 240 may have an EM trackingsensor embedded within or attached to the ultrasound wand, for example,a clip-on sensor or a sticker sensor. Ultrasound sensor 240 may bepositioned in relation to tool 230 such that tool 230 is at an angle tothe ultrasound image plane, thereby enabling the clinician to visualizethe spatial relationship of tool 230 with the ultrasound image plane andwith objects being imaged. Further, the EM tracking system may alsotrack the location of ultrasound sensor 240. In some embodiments, one ormore ultrasound sensors 240 may be placed inside the patient's body. TheEM tracking system may then track the location of such ultrasoundsensors 240 and tool 230 inside the patient's body. Ultrasoundworkstation 250 may be used to configure, operate, and/or view imagescaptured by ultrasound sensor 240. Likewise, computing device 80 may beused to configure, operate, and/or view images captured by ultrasoundsensor 240, either directly or relayed via ultrasound workstation 250.

Various other instruments or tools, such as LIGASURE® devices, surgicalstaplers, etc. available from Covidien LP, a division of Medtronic PLC,may also be used during the performance of the medical procedure. Inembodiments where tool 230 is a microwave ablation probe, the microwaveablation probe may be used to ablate a lesion or tumor at a targetlocation by using microwave energy to heat tissue in order to denatureor kill cancerous cells. The construction and use of a system includingsuch an ablation probe is more fully described in co-pending U.S. PatentApplication Publication No. 2016/0058507, entitled MICROWAVE ABLATIONSYSTEM, filed on Aug. 26, 2014, by Dickhans, U.S. Pat. No. 9,247,992,entitled MICROWAVE ABLATION CATHETER AND METHOD OF UTILIZING THE SAME,filed on Mar. 15, 2013, by Ladtkow et al., and U.S. Pat. No. 9,119,650,entitled MICROWAVE ENERGY-DELIVERY DEVICE AND SYSTEM, filed on Mar. 15,2013, by Brannan et al., the entire contents of each of which are herebyincorporated by reference.

As noted above, the location of tool 230 within the patient's chest maybe tracked during the medical procedure. An example method of trackingthe location of tool 230 is by using the EM tracking system, whichtracks the location of tool 230 by tracking sensors attached to orincorporated in tool 230. Various types of sensors may be used, such asa printed sensor, the construction and use of which is more fullydescribed in co-pending U.S. Patent Application Publication No. US2016/017487314/919,950, entitled “MEDICAL INSTRUMENT WITH SENSOR FOR USEIN A SYSTEM AND METHOD FOR ELECTROMAGNETIC NAVIGATION”, filed Oct. 22,2015, by Greenburg et al., the entire contents of which are incorporatedherein by reference. A percutaneous treatment system similar to theabove-described system 200 is further described in co-pending U.S.Patent Application Publication No. 2016/0317224, entitled “MICROWAVEABLATION PLANNING AND PROCEDURE SYSTEMS”, filed on Apr. 15, 2016, byGirotto et al., the entire contents of which are incorporated herein byreference.

While the above-described system 200 uses a microwave generator 270 toprovide microwave energy to tool 230, those skilled in the art willappreciate that various other types of generators and tools may be usedwithout departing from the scope of this disclosure. For example, radiofrequency (RF) ablation tools receiving RF energy from RF generators maybe substituted for the microwave generators and ablation tools describedabove.

Turning now to FIG. 3, there is shown a flowchart of an illustrativemethod of performing diagnosis and/or treatment of an area of apatient's lungs, in accordance with an embodiment of this disclosure.Starting at step S302, computing device 80 receives image data of thepatient's lungs. In some embodiments, image data from multiplepre-operative scans may be used in combination. In other embodiments,only image data from a most recent scan may be used. The image data maybe received in, or converted to, a uniform data format, such as thedigital imaging and communications in medicine (DICOM) standard. Todistinguish the image data received at step S302 from image datareceived during additional scans performed at various times during themedical procedure, as described below, the image data received at stepS302 will hereinafter be referred to as “first image data.”

Next, at step S304, application 81 processes the first image data toidentify an organ in the patient's body in the first image data. Forexample, application 81 may identify the patient's lungs, andparticularly, the bronchial network of the patient's airways in thefirst image data. The image processing may include automatic and/oruser-assisted image analysis to identify the patient's lungs in thefirst image data. Various image processing methods may be used,including region growing techniques, as described in co-pending U.S.Patent Application Publication No. 2016/0038248, entitled “TREATMENTPROCEDURE PLANNING SYSTEM AND METHOD”, filed on Aug. 10, 2015, byBharadwaj et al., and co-pending U.S. Patent Application Publication No.2016/0005193, entitled “SYSTEM AND METHOD FOR SEGMENTATION OF LUNG”,filed on Jun. 30, 2015, by Markov et al., the contents of each of whichare incorporated herein by reference. Application 81 may furtherdetermine the locations of other structures, such as arteries and veinsof the patient's vascular tree, and/or lymphatic lumens and nodes of thepatient's lymphatic tree.

Thereafter, at step S306, application 81 generates a three-dimensional(3D) model of the patient's lungs. The 3D model includes graphicalrepresentations of the patient's lungs, showing the locations of thelumens and structures of the bronchial, vascular, and lymphatic trees,as well as the pleural surfaces and fissures of the patient's lungs,and/or tumors or other aberrant structures that may be present in thepatient's lungs, as was identified in step S304. Next, at step S308,application 81 receives or loads a model lymph node map and/or a modelvascular tree map. The model lymph node map may be a map showing thelocations of lymph nodes in a model patient's body, and the modelvascular tree map may be a map showing the locations of vascularstructures in a model patient's body. An example of such a model lymphnode map is the International Association for the Study of Lung Cancer's(IASLC) lymph node map. However, other model lymph node maps and modelvascular tree maps may also be used and/or generated based on datacollected from the patient and/or other patients with similar bodytypes.

At step S310, the model lymph node map and/or model vascular tree map isfitted to the 3D model. For example, the model lymph node map and/ormodel vascular tree map may be overlaid onto the 3D model and adjustedto fit the contours and locations of structures in the 3D model. Forexample, the model lymph node map and/or model vascular tree map mayscaled to fit various anchor points, such as the structures identifiedin step S304, and/or may be tethered to various contours of thepatient's body as reflected in the 3D model.

Application 81 then, at step S312, generates a lymphatic tree map and/orvascular tree map based on the model lymph node map and/or modelvascular tree map as fitted to the 3D model. The lymphatic tree mapand/or vascular tree map may be separate maps from the 3D model and/ormay be selectively displayable layers of the 3D model. Thus, thelymphatic tree map will be a map of the expected locations of lymphnodes fitted to the patient's body based on the 3D model, and thevascular tree map will be a map of the known locations of vascularstructures fitted to the patient's body based on the 3D model.

In some embodiments, following step S312, a navigation phase, asdescribed above, may commence. The navigation phase may include theendobronchial navigation of LG 92 and/or tool 62 of system 100 to atarget location in the patient's chest to obtain a biopsy at the targetlocation. Alternatively, the navigation phase may include thepercutaneous and/or laparoscopic insertion into the patient's chest andnavigation of tool 230 to the target location. In some embodiments, anavigation phase may not be necessary to identify the locations of lymphnodes, because predictive models can be generated such that, based onthe position and interaction of the target location and the lymphaticand vascular networks, a number of suggested locations of where toobtain tissue samples may be identified before an exploratory navigationor treatment is performed. During the navigation phase, various toolsmay be navigated about the patient's chest to identify one or morelesions and/or lymph nodes. For example, after reviewing the 3D model,vascular tree map, and/or lymphatic tree map, the clinician may identifya lesion or area of interest in the patient's lungs. The clinician maythen navigate one or more of the tools described above to the lesion orarea of interest in the patient's lungs. When the tool has beennavigated proximate a lesion or area of interest, the position of thetool may be marked on the 3D model as a location of the lesion or areaof interest. The tool may then further be navigated to detect thepresence and locations of lymph nodes and/or vascular structuresproximate the lesion or area of interest. For example, various cameratools, light sensors, and/or linear ultrasound scopes may be navigatedabout the patient's chest to detect the presence and locations oflesions, vascular structures, and/or lymph nodes. In addition todetecting the presence and locations of lesions, vascular structures,and/or lymph nodes, one or more tissue samples may also be obtained frombiopsies of the lesions and/or lymph nodes during the navigation phase.In other embodiments, the navigation phase does not commence immediatelyfollowing step S312, and instead commences after step S322, describedbelow.

Regardless, at step S314, application 81 receives locations ofidentified lymph nodes and/or vascular structures. The locations may bebased on the detected locations of lymph nodes and/or vascularstructures via the use of tools if a navigation phase commenced afterstep S312, as described above. For example, an ultrasound imaging toolmay be used during the navigation phase to acquire image data of variousstructures about and/or proximate the target location. Additionally,various surgical approaches, including mediastinoscopy, video-assistedthoracic surgery (VATS), Chamberlain procedure, etc., may be undertakento identify lymph nodes and/or vascular structures about and/orproximate the target location. Alternatively, or in addition, thelocations may be based on locations of lymph nodes and/or vascularstructures marked and stored during prior procedures. Further still, thelocations may be based on the image processing performed at step S304and/or additional image processing performed thereafter, whether on thefirst image data received at step S302 or on additional image datareceived at step S314, to identify locations of lymph nodes and/orvascular structures in the first image data. For example, one or morescans, such as MRI scans, PET scans, gallium scans, ultrasound scans,etc., may be performed and the image data from such scans received andprocessed by computing device 80 at step S314 to identify the locationsof lymph nodes and/or vascular structures. As such, lymph nodes andvascular structures outside of the patient's chest may also beidentified at step S314 and included in the lymphatic tree map and/orvascular tree map, respectively.

Thereafter, at step S316, application 81 compares the locations of lymphnodes and vascular structures received at step S314 to the lymphatictree map and vascular tree map, respectively, as generated at step S312,to determine whether the received locations of lymph nodes and vascularstructures correlate with the lymphatic tree map and/or vascular treemap, respectively. If the received locations of lymph nodes and/orvascular structures do not correlate with the lymphatic tree map and/orvascular tree map, application 81 updates the lymphatic tree map and/orvascular tree map at step S318. For example, locations of lymph nodesand/or vascular structures detected during navigation and/or identifiedin the first image data received at step S302 and/or the additionalimage data received at step S314 may be compared with locations of lymphnodes and/or vascular structures in the lymphatic tree map and/orvascular tree map, respectively, and the lymphatic tree map and/orvascular tree map may be updated and/or adjusted based on the detectedand/or identified locations of lymph nodes and/or vascular structures.Additionally, for lymph nodes or other structures of which tissuesamples were obtained during a navigation phase following step S312, orprior to the start of the current procedure, and results of analysis ofsuch tissue samples are available, the lymphatic tree map, vascular treemap, and/or 3D model may further be updated to reflect the results ofsuch analysis. For example, if a tissue sample obtained from a lymphnode tests positive for the presence of cancer cells, such a lymph nodemay be displayed in a different manner and/or different color in thelymphatic tree map to identify the lymph node as testing positive forcancer.

Thereafter, or if the received locations match the lymphatic tree mapand/or vascular tree map (and thus no updating is necessary) application81 displays the lymphatic tree map and/or vascular tree map, such as ona display 506, described below with reference to FIG. 5, at step S320.Application 81 may also display the 3D model. As noted above, thelymphatic tree map and/or vascular tree map may be separate mapsdisplayed in conjunction with the 3D model, and/or be selectivelydisplayable layers of the 3D model.

Application 81 may then, at step S322, identify one or more lesionsand/or tumors in the 3D model. The identification may be based on inputreceived from the clinician and/or image analysis of the first imagedata received at step S302 and/or the additional image data received atstep S314. In embodiments, application 81 may highlight (or in someother way display) one or more areas as potential lesions and/or tumorsdetected via image analysis of the image data for review by theclinician. The clinician may then confirm whether the highlighted areasare lesions and provide input to application 81 to mark the confirmedlesions as target locations in the 3D model. The clinician may alsoselect one or more lesions and/or target locations by viewing the imagedata and/or the 3D model. For example, by using input device 510 anddisplay 506 of computing device 80 (described below with reference toFIG. 5), the clinician may view the image data and/or 3D model and mayidentify and select one or more lesions and/or target locations. Theclinician may also select and/or mark various areas of the image data toidentify those areas as areas that may require diagnosis and/ortreatment. Thereafter, application 81 may identify and mark one or morelocations in the 3D model that correspond to the locations marked by theclinician.

Application 81 may automatically, or with input from the clinician,generate a diagnosis and/or treatment plan, as described further in U.S.Patent Appl. Publ. No. 2016/0038248, noted above. As will be appreciatedby those skilled in the art, consistent with the current iLogic™planning system described in U.S. Patent Appl. Publ. No. 2016/0038248,this treatment plan generation may also occur prior to the generation ofthe 3D model by simply viewing the image data, without departing fromthe scope of this disclosure.

After one or more lesions are identified and marked as target locations,the 3D model may be registered with the patient's body, as describedabove. Thereafter, during the navigation phase, application 81, via EMtracking system 70, tracks the location of EM sensor 94 as a tool, suchas LG 92 or tools 62, 64, is navigated about the patient's airways. Forexample, application 81 receives EM tracking data from EM trackingsystem 70 regarding the position of EM sensor 94 within the EM fieldgenerated by EM field generator 76 and processes the EM tracking data todetermine the location of EM sensor 94 within the patient's airways.Those skilled in the art will appreciate that in a percutaneous orlaparoscopic embodiment, an EM sensor coupled to tool 230 may similarlybe tracked, as described above, without departing from the scope of thisdisclosure. Application 81 then displays the tracked location of EMsensor 94 on the 3D model, thereby providing an indication of thelocation of the tool inside the patient's airways. As described above,in some embodiments the navigation phase commences after step S312.Thus, in such embodiments, the tool may already be at the targetlocation or may merely need to be repositioned to the target location.In other embodiments, the navigation phase may first commence after stepS322, and thus in such embodiments the above-described steps of thenavigation phase may be performed after step S322. In either embodiment,after the tool has been placed at the target location, a lesion at thetarget location may be injected with a radiopaque element, such asradio-tagged whole blood from the patient, a collagen tracer, ametabolic tracer such as radiolabeled glucose, a radiation tracer orother isotopes such as gallium along with radiolabeled antibodies,and/or radiolabeled gas that may be inhaled by the patient instead ofinjected.

After the lesion or the lymph node has been injected with the radiopaqueelement, one or more additional scans of the patient's chest may beperformed to acquire second image data of the patient's chest. Forexample, one or more fluoroscopic and/or ultrasound scans may beperformed, but, as mentioned above, those skilled in the art willrecognize that other imaging modalities may also be used withoutdeparting from the scope of this disclosure. The additional scans may beperformed after a period of time has elapsed since the radiopaqueelement was injected into the lesion to enable the radiopaque element tobe spread via the patient's lymphatic system. Application 81 thenreceives the second image data from the one or more additional scans atstep S324.

Thereafter, at step S326, application 81 processes the second image datato identify the radiopaque element injected into the lesion. Theidentification may be performed using image analysis and processingtechniques, similar to those described above. Additionally, application81 may analyze dynamic regional flow distribution and/or aventilation/perfusion ratio within the various branches of the vascularand/or lymphatic lumens emanating from the location where the radiopaqueelement is injected.

Application 81 may then, at step S328, determine whether adrainage/distribution path of the radiopaque element can be detected.For example, application 81 may determine whether the radiopaque elementis detectable in a plurality of lymph nodes and/or lymphatic lumensemanating from the lesion where the radiopaque element was injectedand/or whether the radiopaque element is detectable in one or more bloodvessels draining from the target location. The determination may bebased on whether the radiopaque element is detectable in a predeterminednumber of lymph nodes and/or a predetermined distance from the lesion inlymph ducts and/or blood vessels. The determination may further be basedon whether the drainage of the radiopaque element has not spread farenough yet, and/or that the radiopaque element has become too diluted tobe detectable. If application 81 determines that a drainage/distributionpath of the radiopaque element is not detectable, processing returns tostep S326. Application 81 may also cause computing device 80 to displayan error message indicating the reason why a drainage/distribution pathcould not be determined.

Alternatively, if application 81 determines that a drainage/distributionpath can be detected, processing proceeds to step S330, whereapplication 81 further processes the second image data to identify asentinel lymph node in a drainage/distribution path. A sentinel lymphnode is a lymph node proximate the lesion from which one or moredrainage/distribution paths emanate. After identifying a sentinel lymphnode, application 81 may further process the second image data, at stepS332, to trace a drainage/distribution path emanating from the sentinellymph node to identify other lymph nodes in the drainage/distributionpath and/or blood vessels draining from an area proximate the sentinellymph node. The drainage/distribution path may include all lymph nodesalong a path in which the radiopaque element can be detected, and allblood vessels draining from areas proximate such lymph nodes. In someembodiments, application 81 may further identify directions of fluidflow in the lymphatic and/or vascular networks both leading to and awayfrom the sentinel lymph node and other lymph nodes identified in thedrainage/distribution path and/or the target location. The directions offluid flow may then be indicated on the lymphatic tree map and/or thevascular tree map. Application 81 may further identify a relationshipbetween the directions of fluid flow in various branches of thelymphatic and/or vascular networks, such as by performing a flowassessment based on weighted averages of the fluid flow and/or flowpatterns, etc. At various lymph nodes along the drainage/distributionpath, other drainage/distribution paths may branch off from the drainagedistribution path being traced. Application 81 may then, at step S334,display the identified lymph nodes in the drainage/distribution path onthe lymphatic tree map, and the identified blood vessels draining fromsuch lymph nodes on the vascular tree map.

Thereafter, at step S336, application 81 determines whether alldrainage/distribution paths have been traced. For example, application81 may determine whether additional drainage/distribution paths orbranches emanating from the lesion, the sentinel lymph node, or anyother lymph node down any of the drainage/distribution paths, have to beanalyzed. If additional drainage/distribution paths have to be analyzed,processing returns to step S330. Alternatively, if application 81determines that all drainage/distribution paths have been analyzed,processing proceeds to step S338.

At step S338, application 81 selects one or more of the lymph nodesidentified at steps S330 and/or S332 to be biopsied to determinewhether, and how far, disease has spread. For example, application 81may select the lymph nodes in which the radiopaque element was detectedfurthest from the lesion. In another example, application 81 may selectlymph nodes a predetermined distance from the lesion. For example,application 81 may select lymph nodes which are at least 5 cm from thelesion and/or sentinel lymph node. In another example, application 81may select lymph nodes which are between 7 cm and 10 cm from the lesionand/or sentinel lymph node. In yet another example, application 81 mayselect lymph nodes which are at least three lymph nodes removed from thesentinel lymph node down the distribution path, that is, the selectedlymph nodes have at least three other lymph nodes in the distributionpath between the selected lymph nodes and the sentinel lymph node.Thereafter, at step S340, application 81 displays the lymph nodes to bebiopsied on the lymphatic tree map. The lymph nodes to be biopsied maybe ranked in an order from most likely to include spread of cancerouscells to least likely. The clinician may then select which lymph nodesto biopsy. Application 81 may further generate and display a navigationplan for navigation a tool to the lymph nodes selected to be biopsied.

FIG. 4 illustrates an exemplary graphical user interface (GUI) includinga 3D model of a patient's chest overlaid with a lymphatic tree map, asdescribed above. The 3D model includes a bronchial tree 402 showing thetrachea and the various bifurcations of the airways. The 3D modelfurther includes vascular structures 404, such as major arteries andveins, as well as lymph nodes 410 of the lymphatic tree map, and aselected target location 420. The GUI of FIG. 4 may be displayed bycomputing device 80 at various stages of the above-described medicalprocedure, for example, at steps S320, S334, and/or S340.

FIG. 5 illustrates a simplified block diagram of computing device 80.Computing device 80 may include a memory 502, a processor 504, a display506, a network interface 508, an input device 510, and/or an outputmodule 512. Memory 502 may store application 81 and/or image data 514.Application 81 may, when executed by processor 504, cause display 506 topresent user interface 516. Application 81 may also provide theinterface between the tracked position of EM sensor 94 and the image andplanning data developed in the pathway planning phase.

Memory 502 may include any non-transitory computer-readable storagemedia for storing data and/or software that is executable by processor504 and which controls the operation of computing device 80. In anembodiment, memory 502 may include one or more solid-state storagedevices such as flash memory chips. Alternatively or in addition to theone or more solid-state storage devices, memory 502 may include one ormore mass storage devices connected to the processor 504 through a massstorage controller (not shown) and a communications bus (not shown).Although the description of computer-readable media contained hereinrefers to a solid-state storage, it should be appreciated by thoseskilled in the art that computer-readable storage media can be anyavailable media that can be accessed by the processor 504. That is,computer readable storage media includes non-transitory, volatile andnon-volatile, removable and non-removable media implemented in anymethod or technology for storage of information such ascomputer-readable instructions, data structures, program modules orother data. For example, computer-readable storage media includes RAM,ROM, EPROM, EEPROM, flash memory or other solid state memory technology,CD-ROM, DVD, Blu-Ray or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by computing device 80.

Network interface 508 may be configured to connect to a network such asa local area network (LAN) consisting of a wired network and/or awireless network, a wide area network (WAN), a wireless mobile network,a Bluetooth network, and/or the internet. Input device 510 may be anydevice by means of which a user may interact with computing device 80,such as, for example, a mouse, keyboard, foot pedal, touch screen,and/or voice interface. Output module 512 may include any connectivityport or bus, such as, for example, parallel ports, serial ports,universal serial busses (USB), or any other similar connectivity portknown to those skilled in the art.

Detailed embodiments of devices, systems incorporating such devices, andmethods using the same as described herein. However, these detailedembodiments are merely examples of the disclosure, which may be embodiedin various forms. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as abasis for the claims and as a representative basis for allowing oneskilled in the art to variously employ this disclosure in appropriatelydetailed structure. While the preceding embodiments are described interms of bronchoscopy of a patient's airways, those skilled in the artwill realize that the same or similar devices, systems, and methods maybe used in other lumen networks, such as, for example, the vascular,lymphatic, and/or gastrointestinal networks as well.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

What is claimed is:
 1. A method for mapping a patient's lymphaticsystem, the method comprising: generating a three-dimensional (3D) modelof a bronchial network in a chest of the patient based on first imagedata of the chest of the patient; generating a lymphatic tree map byfitting a model lymph node map to the 3D model; receiving locations of aplurality of identified lymph nodes; updating the lymphatic tree map bycorrelating the locations of the plurality of identified lymph nodeswith the lymphatic tree map; displaying the updated lymphatic tree map;receiving second image data of the chest of the patient; identifying aradiopaque element injected into a target in the second image data;determining a distribution path from the target based on the radiopaqueelement identified and the lymphatic tree map as updated; identifying asentinel lymph node based on the distribution path; displaying thesentinel lymph node identified on the lymphatic tree map as updated;identifying a lymph node in the distribution path a predetermineddistance from the sentinel lymph node; and displaying the lymph nodeidentified on the lymphatic tree map as updated.
 2. The method accordingto claim 1, wherein the plurality of lymph nodes are identified based onimage processing of the first image data.
 3. The method according toclaim 1, wherein the lymph nodes are identified based on electromagneticsensor (EM) data received from an EM sensor coupled to a tool beingnavigated about the chest.
 4. The method according to claim 1, whereinthe lymph nodes are identified based on return signals received from alinear ultrasound scope.
 5. The method according to claim 1, furthercomprising identifying a lesion in the 3D model.
 6. The method accordingto claim 5, wherein the target is a lymph node proximate the identifiedlesion.
 7. The method according to claim 1, wherein the radiopaqueelement is one of: radio-tagged whole blood from the patient; a collagentracer; and a radiation tracer.
 8. The method according to claim 1,wherein the predetermined distance is at least about 5 cm.
 9. The methodaccording to claim 1, wherein the predetermined distance is betweenabout 7 cm and about 10 cm.
 10. The method according to claim 1, whereinthe lymph node identified is a lymph node with at least three otherlymph nodes between the lymph node identified and the sentinel lymphnode.
 11. The method according to claim 1, further comprising:determining areas to which spread may occur based on the sentinel lymphnode identified and the distribution path; and displaying the areas towhich spread may occur on the lymphatic tree map as updated.
 12. Themethod according to claim 1, wherein the model lymph node map isInternational Association for the Study of Lung Cancer (IASLC) lymphnode map.